really hope you can help me here, i have a 12.04 server and a linux pc at home which i set up ssh keygen for with no problems, i want to now gain laptop entry to the server [win7] using putty, i have made the private key and public one, copy and pasted the public one to a new file called authorized_keys2 and moved that file into .ssh/authorized_keys .. before i did that i sudo chmod 600 authorized_keys2

Then put the key private key into pageant started putty put host name in etc, and its not working, i know or feel i missing permission here or something clearly not set right, anyone share any thoughts on this?
After 3 failed login,s i get locked out by Fail2ban, which i happy with, its working. lol
Or at least i hope thats all thats wrong, at the minute i cant gain entry, will wait 10 mins before trying , been reading a lot on how to do this, but no one says it clearly for using a second key through putty.
Thanks people, look forward to your reply.

hi thanks for your reply, yea i made the keys using puttygen, and have the public key on usb and loaded into the server /etc/known_hosts .. no work, i even tried putting into /ssh/authotized_keys, no work.. i then made a new file called authorized_keys2 and chmod 600, then mv to /ssh/authotized_keys, this of course was a bad move, it over ride the key in there and locked me out of server, after 2 hours work i got it removed and new key set set up using keygen on my tower pc, back to where i started now. Where does the public key go that puttygen made? I lost on this.
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jamjamDec 6 '12 at 16:14

@jamjam Make sure you export the public key in OpenSSH format and put this in /home/user/.ssh/authorized_keys. Recursively set permissions correct: chown -R user:user /home/user/.ssh and chmod -R go-rwx /home/user/.ssh. OpenSSH server is quite picky on this. Also make sure to check var/log/auth.log for errors on this level.
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gertvdijkDec 6 '12 at 16:17

Please remember this is the second key, first key works fine and sits in .ssh/authorized_keys i not do this.. chmod -R jamjam:jamjam go-rwx~/.ssh i have however chmod -R jamjam:jamjam .ssh chmod 700 .ssh chmod 600 .shh/authorized_keys and my pc tower key works fine, please if we could start with where the key goes, do i have to put it into .ssh/authorized_keys and then set the permission up right by doing chmod -R go-rwx /home/user/.ssh?? Thanks for helping me hey, need it. lol
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jamjamDec 6 '12 at 16:29

Back again, checked permission on the .ssh/ i got drwx------
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jamjamDec 6 '12 at 16:45